A pressure measuring device of the field of the invention is disclosed, for example, in European Patent EP 1 128 172 B1. The pressure measuring device disclosed there includes a pressure measuring cell in a housing, wherein the pressure measuring cell is oriented essentially coaxially with the housing, and wherein the pressure chamber of the pressure measuring cell is contactable with a media pressure via the pressure duct and a hydraulic path of a pressure transfer means. The pressure measuring cell includes a capacitive transducer whose electrodes are arranged in the pressure chamber and, thus, are surrounded by the pressure transfer liquid. This protects the electrodes in the case of application of the pressure measuring device as a relative pressure sensor against moisture influences that it would be exposed to in the case of an arrangement outside of the pressure chamber. At least one electrode of the capacitive transducer, which is arranged on the platform opposite the measuring membrane, is contacted via an electrical cable, which—same as the pressure duct—leaves on that end of the platform, which faces away from the measuring membrane and toward the pressure transfer means.
Insofar as the capacitance dependent primary signals are sensitive to disturbances, the primary signals must be conditioned as near as possible to the electrodes by a preprocessing circuit. Therefore, between a platform of the pressure transfer means and that of the pressure measuring cell, sufficient space must be provided for such a preprocessing circuit. Moreover, between the lateral surface of the pressure measuring cell and the housing wall, sufficient space must remain, in order to lead the connection lines for the preprocessing circuit past the pressure measuring cell to a main electronics.
Therefore, in the case of a given size of the pressure measuring cell, the housing must be sufficiently large, or, in the case of a given housing size, the pressure measuring cell must be sufficiently small, in order to satisfy the above requirements.
The enlarged separation between the pressure measuring cell and the body of the pressure transfer mean, effects, in addition to the associated greater amount of hydraulic transfer liquid, a contribution to a temperature dependent measurement error. Additionally, it contributes to a hydrostatic measurement error, which depends both on position as well as also on temperature.